inversion

Matrix implementation benchmarks, should I whip myself?

Hello. I'm trying to find out some matrix multiplication/inversion benchmarks online. My C++ implementation can currently invert a 100 x 100 matrix in 38 seconds, but compared to this benchmark I found, my implementation's performances really suck. I don't know if it's a super-optimized something or if really you can easily invert a 200 ...

Flex: Inverting LinearAxis values

I have a line chart that is updated every so and so seconds, similar to the one you see in Windows' Task Manager. The chart goes right-to-left, with the most recent data on the right, and going leftwards. How would I invert the values of the X axis so that the lowest value is on the right and the highest on the left? It's a LinearAxis. ...

Possible ways to calculate X = A - inv(B) * Y * inv(B) and X = Y + A' * inv(B) * A

Hi, I have two problems. I have to calculate two equations: X = A - inv(B) * Y * inv(B) and X = Y + A' * inv(B) * A where, A, B and Y are known p*p matrices (p can be small or large, depends the situation). Matrices are quite dense, without any structure (except B being non-singular of course). Is it possible to solve X in those e...

Which one is faster / more stable: inverting matrix or solving three systems of linear equations with multiple right hand sides?

Hi, I have two equations I'm solving on each recursive round: X = A - inv(B) * Y * inv(B), X = X + A' * inv(B) * A, I solve the problem this way: C = inv(B)Y <=> BC = Y, solve C. D = Cinv(B) <=> DB = C <=> B'D' = C', solve D' E = inv(B)*A <=> BE = A, solve E. All matrices change over time, so I have to do this (or inverting) again...

Inverting panning on MKMapView

Hi, Has anyone been able to intercept touches on MKMapView in order to pan in exactly the opposite direction the user flicks their finger? Thanks! Flyx ...

Octave inverse matrix and integer result

Hi, I would like to get an invertible matrix in Octave but as integers matrix, so: x = [9,15;19,2]; inv(x) and the result is: [-0.0074906, 0.0561798; 0.0711610, -0.0337079] but I would like to get [22,17;25,21] anyone knows how to convert this result? Many thanks. ...

Is there a standard library implementation of MPI inverse matrix calculation problem?

Is MPI implementation of matrix inversion a standard library routine or good MPI implementation critically depends on your setup(software/hardware) so have to be coded by yourself. ...

SQL select inverted tree

Hello i have tree structure in sql. Logics is standard: SomeID, ParentID, other fields. I have select procedure, which selects data like this: 1. 1.1 1.1.1 and so on. How to write the select procedure, to get the inverted result(first are selected the deepest branches, last - root branches), like this: 1.1.1. 1.1. 1. 2.2.2.2.2. 2.2....

Invert the 1bbp color under a rectangle.

I am working with GDI+, the image I am working with is a 1bbp image. What i would like to do is draw a rectangle on the image and everything under that rectangle will be inverted (white pixels will become black and black pixels become white). All of the sample code I have seen is for 8 bit RGB color scale images, and I don't think the t...

Text Invertion Android

Hi Anybody knows how to write upside down text of edit text in Android thanks /minhaz ...

question about inversion

Hi I have read something in the site that inversion means if i<j then A[i]>A[j] and it has some exercises about this , I have a lot of questions but I want to ask just one of them at first and then i will do the other exercises by myself if I can!! Exercise: What permutation array (1,2, ..., n) has the highest number of inversion? What ...

Inversion for insertion sort!

This a question I found in the Wikipedia site (I want to learn sort algorithms very well). Anyway, this is a question - could you explain to me how I can show it? Exercise: Show that Algorithm Insertion Sort (A) runs in time O(n + I) given that I is the number of inversions in the array A. ...

inversion pairs in an array - application

I came across an algorithmic problem to find out the number of inversion pairs in an array in O(nlogn) time. I got the solution to this. But, my question is that what is the real-life application of this problem? Like I want to know some applications where we need to know the inversion pairs. ...

Difference between "Inversion of Control", "Dependency inversion" and "Decoupling"

I'm reading theory about dependency inversion and decoupling and I can't see the difference between the two. Dependency inversion talks about decoupling functional components so that higher level components don't depend on lower level components. Decoupling talks about the same thing and how to achieve it. But then we have IoC Containe...

How do I turn any regex into an complement of itself without complex hand editing?

The following are pseudo examples, not real regex, but still an example of what I mean: .* (anything) -.* (NOT anything) [A-Z] (Any letter A to Z, caps only) -[A-Z] (NOT any letter A to Z, caps only) EDIT: Changed inverse into complement in the question. Here's where the change was made: "turn any regex into an complement of...